Box2DPosUpdater = function(go, box2dbody, box2dsys) {
    this.gameObject = go;
    this.box2dbody = box2dbody;
    this.box2dsys = box2dsys;
};

Box2DPosUpdater.prototype = Object.create(Updater.prototype);

Box2DPosUpdater.prototype.run = function() {
    var body = this.box2dbody;
    var go = this.gameObject;
    var b2dpos = body.GetPosition();

    if (this.box2dsys) {
        go.x = this.box2dsys.mtp(b2dpos.x);
        go.y = this.box2dsys.mtp(b2dpos.y);
    } else {
        go.x = b2dpos.x;
        go.y = b2dpos.y;
    }
};
